Electrical-conduit attachment.



L. H. CHURCH 51: A. MGMURTRIE.

ELECTRICAL GONDUIT ATTACHMENT.

APPLICATION FILED 1311.15 1911.

LlwS lfifi Patented Feb. 9, 1915.

Immu

A. IvioMURTRIB.

ELECTRICAL 00mm I? ATTACKS-EH11".

L. H. CHURi-H APPLIGATIOE? FILED APRJS 1911,

Ea-tented Feb. *9, 1915.

gest:

be illustrated and described fully in the accompanving drawings and specification, and set forth in the claims.

In the drawings, Figure 1 is a view in plan looking from bottom to top of a box for electrical conduit, in the construction of which our invention has been embodied; Fig. 2 is a similar view in plan looking from top to bottom of said box; Fig. 3 is a vertical sectional view of said box on the line 3-3, Fig. 1 looking in direction of arrows; Fig. 4 is a view in perspective partly in section of the box shown in Fig. 1; Figs. 5

and 10are views of gripping members of various forms; Figs. 6, 7, 8 and-9 are views similar to Figs. 1, 2, 3 and 4 respectively, of an electrical conduit box of modified form; and Fig. 11 shows a modified form of gripping member.

In theembodiment of our invention for illustratibn and description to enable ready and complete understanding of our improvements, the part designated by the reference numeral 1 is an outlet box or cable box of a type well known to those skilled in the art of installing electrical conduit systems, and may be. of any suitable shape, material and general arrangement, the form herein shown by way of example being circular, of cast metal, and having several sockets, bushings or seats 2, with apertures 3, and rounded mouths or shoulders 4 of a type usually provided to receive sheaths, such as that shown at 5 for electrical conductors6 pfovided with insulation 7,. the type of conductor shown being what is known as cable, its armor consisting of a spirally wound metal strip, the end 8 of which preferably abuts snugly against the shoulder 4: of the bushing. 4

In accordance with our invention, retain- I ing or grippingmembers 9 are provided for the respective sheaths and may be of any form suitable to carry our invention into effect, each retaining member being shown in the instance illustrated as a bolt comprising a polygonal nut, best seen in Fig. 5, having a suitable o'jperatin member, such as thedraft screw 10, wiich passes at 12 through an aperture 13 in the portion 14 of the bottom wall of the box, the bolt having a slotted head 16 to permit its operation by a screw driver in the hands of the operator, who may work from the face of the box opposite that contaiping the entrance to the bushings or sockets, usually the inner side of the cable box.

In accordance with an important feature of our invention the gripping device is constructed and arranged to be engaged with suitable abutment surfaces 18 and 19 provided upon the lower face of the bottom wall of the box, such surfaces constituting forcing walls, and for that purpose being 66 so arranged that as the bolt is rotated the nut will be drawn into contact with the sheath, and the sheath will be wedged be.

tween the seat for the sheath and the nut and at the same time the nut is drawn upward from the plane of the base, drawing with it the sheath, so that the latter will be seated firmly in its socket against the shoulder 4.

In accordance with another important feature of our invention we prefer to tilt the abutment surfaces, as illustrated, so that the gripping side 20 of the nut will be engaged with the periphery of the sheath in a longer region of physical and electrical contact than would be the case were a rectangular nut drawn along abutment surfaces perpen dicular to the base of the box. This line contact of the gripping member with the periphery of the sheath serves to hold the sheath firmly against rotative and axial displacement and we may provide for it by any suitable construction. For example, as illusto the base of the box, which will otherwise preferably be substantially like the box already described As hereinbefore indicated, we prefer to provide also means acting normallyto hold the nut out of the path of the sheath,'and as one suitable form of device for this purpose, we have shown at 40 a coiled spring upon the shank of each bolt, under compression between the nut and the draft wall portion 14 of the bottom wall of the box, through an aperture 13 in which extends the shank of the bolt, and we prefer to have the recess in which each nut lies of a sufficient size to receive the nut snugly, when thus positioned by the spring, so as to clear the socket 3 entirely, and thus the workman is not hampered in his insertion of each sheath and conductor.

The numeral 60 designates the usual central hole or bushing provided to receive a gas pipe or other means of support for these boxes, which are commonly used upon ceilings and in similar situations, a set screw 61 being provided ordinarily to hold the box in adjusted position. The usual screw holes 62 in the base may also be provided.

If desired, and it w ill usually be found preferable, the gripping nuts may each be nature of an outletbox; comprising a itii. provided with a socket for cond sheath; and a gripping device rroiiipi'i grip anal scpni'zito actuating iiimns tl u sniil "Wall having a forcing sm'i'ac' atan angle to a plum.- pnwewl ii. in general do we limit on longitudinal axis of said 506K131: to than as set forth in the clai road in consaid grip into CllzlgOTlzzi l ne contact with the motion with this specificzitioim pei'i'iheiy of said bllifltli. What in: claim as new and to All electrical conduit member of cure b3 Leltei'g Patent i nutuz'c oi an outlet box: comprising: u i

l. A i an 2211mm sheaili. lli pl'UVld fll with a xoclzot to receive :1 cor:- sa-id member: doctor sliemli; said 110): wall lim'iii a rcand aclizai c ii portion in communication i ll said soclici, mid recess being iocatcd Lil-orig one i'elat side oi, and loll ituclinullv (ilziflmrn? L .mi l

scclict, BZlLi z: gripping device c grip rate actuating me: said grip l 3111;; supported mom rem cl portion and directed by 3,;

iiz'io ietcntive contact with sai' T. in clcctricz-il conduit mm imtui'c ml :21: ooc liuX: comp Wall pi'm'irlcil Wifl soc-kit to l "e a conductor 551 nox wall having a re- 99 c ed ponicii in minmnunication with sairl sockeii, said recess using locutcd along one side of and longiiiudinully diagonal to, said socks; a gripping device compiling a .1 imill EULA il gifip, and separate actuating means ili'lE- f 3 1o grip being supported movably in hcessecl portion, and said actuatin means being opei'aolo from the other face or said box Wall relatively i0: said socket, to i move gi'ipping device inm diagonal 10% line rel niii'e Contact with saifi sheath.

8. An electrical conduit membei of'tho .atui'c of outlet box; comprising a box wall provided with? socket to rece ve a conductor she-2.5m: saici wall ham .g a re ccsssd portion in communication with said chat, said recess being located :ilong one Q of, and longitmiinaliy ilizwonal "zo,-sr:id

t; :1 gripsiipported nim'abiy in said 1 plm'uliby (naive and direct :1 gr

' oping member surfac s; one tilted Hi an i to said anti :1 sc 'ow, extenclingz through said. 116 main J w ll with its head pom e of said will opposite that connming said 1M1 said it, ii' Sl'lfldlk in actuative connect/ion mi-pose with said grip. 50 9. in electrical comluii member of the Lil i .HtLlHf 03 an outlet box, having a l'iotiom provided with a plurality of sockets for conductor sheaths having recessed portions in ommunication wili certain of richer mov Sillll socket :lCll to IGCQiYE :1 gripping mem 128 i lOln bar. the w; i said recessed portions com- QJXUQ," prising respectively a pair of forcing surluth, i'ziccs inclined respectively one at an angle 011g to :1 plane passed through the longitudinal in 1) tion for line co mo a polygonal gripping member i 66 said surfaces. in :1 iii z'non ti tucaxis of said sheath, and the other at an angle 126 gent to. and into l'iill v r M said to a plane p'crpeniculur to u si ica: and on open u n'ieiiilicr liming also (l1'2ii't -\i 'ulls 11cm said said gripping in ii-CBS. and i'8iklli'llll{i 6li5, c0

5, An eieciiical so? i mil gripping out two of Whose- 13$ sides are engaged with a pair of said forcing surfaces, and, a third side is presented for retentive engagement in diagonal line contact with .t sheath in its socket, said draft screws extending one from each of said nuts through said respective draft portions of said bottom Wall, said draft screws having operating heads operable from within said box on the other side of said bottom wa l.

10. The combination with an electrical conduit member of the nature of an outlet box, having sheath-seats and bolts with gripping nuts for retentive engagement with said sheaths, of springs acting to hold said nuts out of the path of said sheaths, respectively; substantially as described.

IL The combination with an electrical conduit member of the nature of an outlet box, having sheath-seats and bolts with gripping nuts for retentive engagement with said sheaths, of coil springs surrounding said bolts .and acting to hold'said nuts away from said seats; substantially as described.

12. The combination with an electrical conduit member of the nature of an outlet box, having a sheath-seat beneath its wall; of a retaining-bolt passing through said wall; a gripping nut on said bolt for reten- .tive engagement with said sheath; and a spring between said nut and Wall to hold said nut normally out of the path of said sheath.

13. The combination with an electrical conduit member having a seat for a conductor sheath, of a gripping device comprising an operating member located alongside of said seat and longitudinally diagonal with reference thereto, and a gripping nut of trapezoidal contour operable along said operating member into engagement with said sheath, said conduit member having a forc- 

